The present invention relates to a method of producing a blend of different acyl gellan gums with starch and a plasticizer having similar textural and functional properties compared to gelatin. The present invention also relates to a method of making films and soft capsules prepared using such blends and the method of making such films and capsules.
Gelatin is used in various pharmaceutical applications including soft gelatin capsules and hard gelatin capsule shells as well as many different food applications. Soft capsules are used to encapsulate a solution or dispersion, for example of a nutritional or pharmaceutical active agent, in a liquid carrier and have many advantages over other dosage forms, permitting accurate delivery of a unit dose in an easy-to-swallow, transportable, essentially tasteless form.
However, gelatin has many drawbacks, including the cost and continuity of a safe supply. Bovine sources are also undesirable to certain individuals, such as vegetarians and those wishing to maintain Kosher or Halal standards. Further, gelatin is prone to crosslinking, caused by aging or due to reaction with compounds such as aldehydes, which reduces its solubility in gastric juices.
Gelatin provides good sealing of the capsule at a temperature above the melting point of the film, a wet film strong enough to survive the manipulation in the encapsulation machine, dissolution in gastric juices, and sufficient elasticity to allow formation of a capsule. With the growing concern of Bovine Spongiform Encephilitis (BSE) disease in products derived from cows, many attempts have been made to replace gelatin, such as the 25-45% present in soft capsules. However, these approaches have typically failed in that the resultant products had unacceptably different textural and/or functional properties.
Surprisingly, it has now been found that the use of a film forming blend of different acyl gellans with starch provides an excellent wet film with a high modulus and excellent strength and elongation. Further, soft capsules made with such blends or films have good sealability.